This is true, but frontline healthcare staff wages are only one part of the problem. For specifics you can see details here (e.g.: US average front-line healthcare worker salary: €74.450, Germany: €40.522):
https://www.qunomedical.com/en/research/healthcare-salary-in...
But even absent any movement there you have a lot of savings to be had away from that:
1. The U.S. medical administration costs have ballooned, in large part because of the highly adversarial billing system between insurers and practitioners. Medicare/Medicaid is much less (but not completely) unpredictable. Doctors complain bitterly about the prices at times, but the system is much more efficient.
2. U.S. insurance companies are woefully inefficient. To the point that companies complained bitterly when the ACA required them to pay out 80% of premiums as medical payments. Before that there were companies making more than 20% profits. The most efficient insurance companies today use about 12% of their revenues for non-medical care. In comparison Medicaid uses about 3.9%.
There are lots of other parts you could address as well:
1. Fraud drawn to the huge payouts for medical bills. If people's accidents were just covered as a normal part of life those payouts, and most of that fraud just goes away.
2. Malpractice insurance. This is like the first, but would mostly be solved by a combination of single payer and a working medical review system (seriously, what we have now is the definition of regulatory capture).